---
title: "A mixture of \\(\\text{N}_2\\text{O}_4\\text{(g)}\\) and \\(\\text{NO}_2\\text{(g)}\\) is at equilibrium inside a rigid cylinder fitted with a movable piston at a constant temperature, as represented by the equation below:  \\[ \\text{N}_2\\text{O}_4\\text{(g)} \\rightleftharpoons 2\\,\\text{NO}_2\\text{(g)} \\]  The piston is pushed inward to decrease the volume of the container at constant temperature. Which of the following best predicts the direction the reaction will shift to re-establish equilibrium, and provides the correct justification?"
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url: "https://nerd-notes.com/ubq/119693/"
date_modified: "2026-08-21T08:12:04+00:00"
---

# A mixture of \(\text{N}_2\text{O}_4\text{(g)}\) and \(\text{NO}_2\text{(g)}\) is at equilibrium inside a rigid cylinder fitted with a movable piston at a constant temperature, as represented by the equation below:

\[ \text{N}_2\text{O}_4\text{(g)} \rightleftharpoons 2\,\text{NO}_2\text{(g)} \]

The piston is pushed inward to decrease the volume of the container at constant temperature. Which of the following best predicts the direction the reaction will shift to re-establish equilibrium, and provides the correct justification?

A mixture of \(\text{N}_2\text{O}_4\text{(g)}\) and \(\text{NO}_2\text{(g)}\) is at equilibrium inside a rigid cylinder fitted with a movable piston at a constant temperature, as represented by the equation below:

\[ \text{N}_2\text{O}_4\text{(g)} \rightleftharpoons 2\,\text{NO}_2\text{(g)} \]

The piston is pushed inward to decrease the volume of the container at constant temperature. Which of the following best predicts the direction the reaction will shift to re-establish equilibrium, and provides the correct justification?

- **A.** The reaction shifts toward the products because decreasing the volume favors the side with more moles of gas.
- **B.** The reaction shifts toward the products because the reaction quotient \(Q\) becomes less than the equilibrium constant \(K\).
- **C.** The reaction shifts toward the reactants because decreasing the volume favors the side with fewer moles of gas.
- **D.** The reaction does not shift because the equilibrium constant \(K\) remains unchanged at constant temperature.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119693/*